urtware / doc / activitydiagrams / subscriber / urtSrtSubscriberFetchLatestMessage.uml @ e87bd7c7
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1 | 7491c395 | Thomas Schöpping | /' |
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2 | µRtWare is a lightweight publish/subscribe middleware for real-time |
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3 | applications. It was developed as part of the software habitat for the |
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4 | Autonomous Mini Robot [1] (AMiRo) but can be used for other purposes as well. |
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5 | |||
6 | Copyright (C) 2018..2020 Thomas Schöpping et al. |
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7 | |||
8 | This program is free software: you can redistribute it and/or modify |
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9 | it under the terms of the GNU General Public License as published by |
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10 | the Free Software Foundation, either version 3 of the License, or |
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11 | (at your option) any later version. |
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12 | |||
13 | This program is distributed in the hope that it will be useful, |
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14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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16 | GNU General Public License for more details. |
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17 | |||
18 | You should have received a copy of the GNU General Public License |
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19 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
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20 | '/ |
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21 | |||
22 | /'### INTRO ##################################################################'/ |
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23 | |||
24 | @startuml |
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25 | |||
26 | ee83a495 | Thomas Schöpping | title **µRtWare**\nurtSrtSubscriberFetchLatestMessage()\n |
27 | 7491c395 | Thomas Schöpping | |
28 | e87bd7c7 | Thomas Schöpping | !include ./functions.iuml |
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30 | ee83a495 | Thomas Schöpping | /'### PARAMETERS & RETURN ####################################################'/ |
31 | 7491c395 | Thomas Schöpping | |
32 | note |
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33 | ee83a495 | Thomas Schöpping | -- **subscriber** : urt_srtsubscriber_t* -- |
34 | The SRT subscriber that shall fetch the message. |
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35 | 7491c395 | Thomas Schöpping | Must not be ""NULL"". |
36 | ee83a495 | Thomas Schöpping | -- **payload** : void* -- |
37 | Pointer where to copy the payload to. |
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38 | May be ""NULL"" for messages without payload. |
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39 | -- **bytes** : size_t -- |
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40 | Payload size in bytes. |
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41 | -- **latency** : urt_delay_t* -- |
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42 | The latency can be returned by reference. |
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43 | May be ""NULL"". |
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44 | ==== |
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45 | -- **return** : urt_status_t -- |
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46 | Returns ""URT_STATUS_OK"" on success. |
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47 | Returns ""URT_STATUS_ERROR"" if the subscriber is not associated to a topic. |
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48 | endnote |
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49 | 7491c395 | Thomas Schöpping | |
50 | /'### PROCEDURE ##############################################################'/ |
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51 | |||
52 | ee83a495 | Thomas Schöpping | start |
53 | if (Associated to a topic?) then (yes) |
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54 | :lock topic; |
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55 | e87bd7c7 | Thomas Schöpping | $find_latest_message() |
56 | $fetch_message() |
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57 | ee83a495 | Thomas Schöpping | :unlock topic; |
58 | stop |
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59 | note |
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60 | Returns ""URT_STATUS_OK"". |
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61 | endnote |
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62 | else (no) |
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63 | stop |
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64 | note |
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65 | Returns ""URT_STATUS_ERROR"". |
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66 | endnote |
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67 | 7491c395 | Thomas Schöpping | endif |
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69 | /'### OUTRO ##################################################################'/ |
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70 | |||
71 | @enduml |